A Key to the More Frequently Occurring Freshwater Algae - Freshwater Algae: Identification, Enumeration and Use as Bioindicators - page 225

2a 2b

1a 1b

A

B

2c

3a

3b

5a

5b

6a 6b

4a 4b

Plate XXIV A/B: general valve view - different orientations of raphe 1 . Encyonema : Type A raphe (a) frustule
markings, (b) chloroplast. 2. Amphora : (a) valve view - frustule markings, (b) valve view - chloroplast, (c) girdle view -
chloroplast. 3. Cymbella : Type B raphe (a) frustule markings, (b) chloroplast. 4. Rhopalodia: (a) valve view, (b) girdle
view. 5. Peronia : (a) valve view, (b) girdle view. 6. Rhoicosphenia: (a) valve view, (b) girdle view.